* Move CSS definitions to resources
* Add Gtk::Builder helpers
* Switch StatsDialog to Gtk::Builder
* Switch RelocateDialog to Gtk::Builder
* Switch OptionsDialog to Gtk::Builder
* Switch MakeDialog to Gtk::Builder
* Switch FilterBar to Gtk::Builder
* Switch MainWindow to Gtk::Builder
* Switch MessageLogWindow to Gtk::Builder
* Switch DetailsDialog to Gtk::Builder
* Switch PrefsDialog to Gtk::Builder
* Fixup translatable strings
Since this branch was brewing for a while, changes happened in the meantime.